Northern Lights Limbo Plus A Comet Takes On A Dragon

Despite a no-show for the light show, many of you noticed the striking pair of Venus and Jupiter in the western sky during twilight last night. Photo: Bob King

You’re not all going to turn your backs on the aurora just yet, are you? Some of us were disappointed that the expected storm didn’t arrive. Even today, there’s no evidence of its arrival. Either it missed us, delivered a much softer blow than anticipated or is still on its way.

Aurora forecasting resembles ordinary weather forecasting in many ways. Forecasters gather the latest information and then use computer modeling to determine a a storm’s track, arrival time and how severe it will be. We’re all familiar with the possible outcomes: meteorologists either nail it, get the idea right but err on the particulars or prove utterly wrong. We must learn to forgive, since nature always has the trump card. To learn more about the sun’s affects on Earth, including the aurora, I think you’ll enjoy this brief primer on space weather.

Auroral storms are still expected today through tomorrow, so it always pays to keep watch. I’ll post an update later today.

Earth's counterclockwise motion around the sun causes the stars and planets to rise 4 minutes earlier in the east each night. Over time, those minutes add up, until current season's constellations are "pushed" off the stage by the next. The cycle comes full circle after a year. Illustration: Bob King

The planets have been a big part of the night sky landscape the past few weeks. Venus and Jupiter dominate the western sky, ruddy Mars is high up in the southeast by mid-evening and Saturn shows up next to Spica in Virgo around 11 o’clock. That used to be 10 o’clock, but no thanks to daylight-saving time, we have to stay up an hour later now to see Saturn.

Not to fret. Earth’s revolution around the sun will conspire to raise the planet in the east 4 minutes earlier each night. In just two weeks that will shave a total of 56 minutes or nearly an hour off its rising time, and we’ll be back to where we started.

Rolando Ligustri compiled four days of photos of Comet Garradd from March 3-6 to show its motion through the sky. The dust tail sticks out to the left; the ion or plasma tail to the right. Credit: Rolando Ligustri

Last night I was excited to see how Comet Garradd’s been doing, so I grabbed my 10×50 binoculars and found it just beyond the Bowl of the Big Dipper in the tail of Draco the Dragon. Since we did our last update, the comet has moved from the morning sky to a very convenient viewing spot right up next to the Dipper. This slow-moving, rather distant but large comet has been hanging around since last summer. All the while, it’s brightness has changed little, remaining around magnitude 6.5. That’s just below the naked eye limit. Garradd was closest to Earth on March 5 at 118 million miles.

In case some of you are wondering why I’m always talking about this comet, it’s the only one in recent months bright enough to enjoy in a small telescope or see in binoculars. The rest are faint.

Last night through binoculars it was a dim, misty patch about 2/3 the size of the moon with a brighter center. Through a 15-inch telescope, Garradd has a bright, fuzzy coma with a small, intense star-like core or nucleus. Two faint, diffuse tails sprout from its head. To see these, you’ll need at least a 6 to 8-inch telescope and dark skies. Garradd will slowly fade through March and April but remain well-placed for viewing. Give it a try now that the moon’s out of the sky.

The Big Dipper, now high in the northeastern sky in the early evening hours, makes it fairly easy to find Comet Garradd. This map shows its position every 3 days through late March. Look for a faint, fuzzy patch in binoculars. The labeled stars, Kappa and Lambda Draconis, are naked eye stars. Other stars shown to about mag. 7. Created with Chris Marriott's SkyMap

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13 Responses

Janice

Thanks for the great info Astro Bob. I’m in New York and missed the end of last week opportunity due to cloud cover. I’m checking many different sites, but how often is the forecast updated at sites like the Auroral Forecast by the University of Alaska? This map link http://www.swpc.noaa.gov/Aurora/globeNW.html shows the kp number 9, but then I check the activity and it is low. Should I check regularly after 10 p.m. overnight for the chance to hop in the car and head north of the light pollution? Any clarification would be appreciated; I get confused looking at all of the different sites.

Hi Janice,
What you want is the live Kp index I’ve been referring to on my blog at: http://www.swpc.noaa.gov/rt_plots/kp_3d.html
It shows the Kp index every three hours. The last column on the right is the most recent estimate of activity. Use that plus look at the trend to help you decide whether to head out or not.
By the way, O hours UT (start of day) = 8 p.m. Eastern Daylight Time the day before. So the vertical line for March 11 means (for your time zone) 8 p.m. March 10. The colored column to the right of that centered on the white tick is 3 hours later (11 p.m.), the next column is 2 a.m. and so on. Just in case you wanted to know the details of the diagram.

Brian,
There’s a possibility tonight through tomorrow night. Before you drive too far, be sure to check the Kp activity index. If you see all green bars on the right side of the graph, it won’t be worth your while. Lots of red bars (high activity) and your chances are much better. The index is at: http://www.swpc.noaa.gov/rt_plots/kp_3d.html

Thanks for the forecast web site. I’m going to be in Minneapolis the week of 26 March, and am hoping for an strong solar event and some northern lights. I have a car and am ready to drive up to Duluth Wed or Thur (28/29 March).
Think my chances this time will be good? Where’s a good place near Duluth?
Are there any groups I could meet up with to wait and watch?
Chris

Chris,
Before coming up, you should be sure there’s a possibility of northern lights. Things may be quiet then. We won’t know until a couple days beforehand what the chances are. Contact me via the Comments link before you come up, so you’ll have an idea if it’s worth the drive.